A network sharing (Network sharing) technology can implement that multiple operators (Operator) provide services for respective users by using one shared mobile network, thereby greatly reducing costs of repeated construction of mobile networks. However, despite many advantages, this type of sharing usually causes increased network complexity. Particularly when the network is faulty, processing becomes more difficult.
A typical scenario is that services provided by multiple operators exist in a cell (Cell) within coverage of one base station. Networks of the operators in the cell may be referred to as PLMNs (Public Land Mobile Network, public land mobile network) of the operators. The PLMNs of the operators share a RAN (Radio Access Network, radio access network) of the cell. A fault occurs in a network of an operator at a moment because of some reasons. For example, an S1 link from the RAN to an MME (Mobility Management Entity, mobility management entity) is broken, as shown in FIG. 1. Because there is no corresponding processing method currently, an abnormal phenomenon may occur, such as a phenomenon that UE (user equipment, User Equipment) still attempts to access the faulty network of the operator, causing a negative impact.